Yes, people know, but a coverup was orchestrated to keep the public from knowing. What we do know, is that Winston had sex with her. We know she was left bruised. We know that she didn't know his name, didn't know who he was, and didn't seem happy to have had sex with him (she reported it shortly thereafter), and it would seem was held down.
That's a lot in the way of facts to go off of...
Edit: Let's examine a scenario in which it wasn't rape. She voluntarily left the bar with a complete stranger, never bother to ask his name or anything about him. She then had consensual sex with the stranger. Then, after this happened, perhaps because he was too rough with her (but consensually of course), she decided to accuse him of rape. But, she had to have decided that after she left, because if this was fixed in her mind at the time, she would have at least asked his name or phone number. So, shortly after they parted ways, she would have decided to report it as rape, and gone in and reported it soon enough for the bruises to show up during the interview.
What human being capable of logical thought really thinks that is what happened? Who decides to falsely accuse someone of rape when they can't even identify the individual? What incentive would she have had to go to the police and do that? And then, additionally take the step of later identifying him once she knew who he was? If she was making a false accusation because of some need for attention, why would she ever have identified Winston? There's only one logical conclusion to reach based on the facts and timeline of what happened.